The subject invention relates to a system for addressing envelopes. More particularly it relates to a system including a laser printer or the like operating under control of a micro-computer or the like to print envelopes with addresses.
It is known, as is taught in U.S. Pat. No 4,397,592; to: Brodesser, to print envelopes using a laser printer or the like. In developing the system of the subject invention Applicants have realized that it is desirable to print envelopes in a "two-up" mode. That is to print envelopes two at a time, short edge first. (In general the paper path of a laser/printer is too narrow and the spacing between drive rollers is to great to allow normal envelopes to be fed long edge first.) Such "two-up" printing is known for use with multilith printers and duplicators, which are used to permit sequences of envelopes with identical information. Such "two-up" feeding of envelopes is taught in U.S. Pat. Nos. 4,603,846 and 4,625,651; to: Miles and Jagas, respectively.
When envelopes are printed "two-up" or, more generally, as a succession of pluralities of envelopes, there is a problem in printing a sequence of M addresses and restoring the printed envelopes to the same sequence. This is desirable because the Postal Service allows substantial postage discounts for pre-sorted mail and because it is frequently necessary to match particular contents with corresponding pre-addressed envelopes. If envelopes are printed "two-up" in the most natural way, with one stream consisting of envelopes printed with the even numbered addresses in the sequence and the other printed with the odd numbered sequence of addresses, the envelope steams will have to be merged envelope by envelope to restore the sequence for the printed envelopes. Further, the output of such a printer will generally be to an output stacker having a limited capacity 2N (two stacks of N envelopes, still considering "two-up" printing) where 2N is generally less than M. Thus, the system must suborder the printed envelopes into groups of N envelopes.
Another problem arises because it is also desirable to have a system where a jam or failure to feed on any paper path halts the system. Thus the system controller must provide for sequences of address which are not multiples of the number of paper paths provided since absence of an envelope on any of the paper paths will otherwise appear to be a jam or failure to feed.
Thus it is an object of the subject invention to provide a system for printing envelopes two or more at a time, with a sequence of consecutive addresses in manner such that the printed envelopes can easily be restored to the address sequence.
Other objects and advantages of the subject invention will be apparent from the attached drawing and detailed description set forth below.